There has been a lot of talk in the national news about fracking, and we aren't talking about "special time" for “Battle Star Galactica” geeks. Hydraulic fracturing (or fracking for short) is a process used in oil or gas drilling where water and other components are injected deep underground to fracture subterranian formations allowing natural gas to come to the surface. According to researchers from the U.S. Geological Survey, there has been a significant increase in earthquakes in the middle of the United States compared to previous years.

The U.S. Geological Survey reports that for the three decades until the year 2000, seismic events across the middle of the nation averaged only 21 per year. Then in 2009 events jumps to 50 per year, in 2010 they increased to 87 per year, and then in 2011 there were 134 reported seismic events. Some are pointing to fracking as the reason for the increase in seismic events across the middle of the United States, which historically has very few seismic events. However, scientists believe that these seismic events are perhaps more related to wastewater disposal underground than fracking.

“Our scientists cite a series of examples for which an uptick in seismic activity is observed in areas where the disposal of wastewater through deep-well injection increased significantly,” David Hayes, the deputy secretary of the U.S. Department of Interior, said in a blog post yesterday, describing research by scientists at the U.S. Geological Survey.

According to Haynes, the seismic events across the middle United States are generally "very small" and rarely cause damage. He also notes that not all instances of fracking or wastewater injection cause seismic issues. Fracking injects contents such as water and some chemicals, into the shale formations within the earth. The point is to break apart underground formations and free natural gas trapped there.

Hayes added, "We also find that there is no evidence to suggest that hydraulic fracturing itself is the cause of the increased rate of earthquakes."

Bloomberg reports that much of that wastewater comes back to the surface and has to be disposed of. This is where the difference between hydraulically fractured wells and disposal injection wells comes into play. Disposal injection is taking the wastewater created from fracking and injecting it back underground.

Daniel Whitten, a spokesman for the America’s Natural Gas Alliance, told Bloomberg, "[There is] a difference between disposal injection wells and hydraulically fractured wells. There are over 140,000 disposal wells in America, with only a handful potentially linked to seismic activity."

However, he did point out that the industry is committed to monitoring the issue and working with authorities when there's a concern about seismic activity in an area.